Multiple personality disorder (MPD) is a strange condition in many ways. One of the rarest and most controversial of all psychological diagnoses, it is at the same time one of the most famous and widely known to the general public. This is despite the fact that, for many researchers, the condition does not actually exist at all! Of all the supposed cases to have been reported, by far the most famous was that of Christine Sizemore, or 'Eve'.

Alternative study - Thigpen and Cleckley as an observational study

Thigpen and Cleckley conducted interviews and tests with Eve/Jane. Another way to investigate her multiple personalities might have been to do an observational study.

1. Describe the observational study as a research method in Psychology. (5)

2. How could they have performed a study with similar aims, but as an observational study?

Write a description of the study, including the who, what, where and how. (10)

3. What would the advantages and disadvantages of such an experiment be, compared to the original?

Evaluate this new study in methodological and ethical terms. (10)

Big Issue - snapshot vs longitudinal data

A longitudinal study is one carried out over a period of weeks months or even years, to allow researchers to see a change in behaviour over time. In contrast, a snapshot study will take place over a few hours or maybe days.

Snapshot

Quicker, easier and cheaper to carry out.

Allows larger samples to be used more easily.

Can't demonstrate changes in behaviour, as it only takes a snapshot

Longitudinal

Can demonstrate change over time, so useful for developmental psychology studies.

Costly and time-consuming

May lead to attrition, where participants drop out of the study over time.

DID and ethnocentric bias?

Dissociative Identity Disorder is diagnosed far more frequently in America than in the rest of the world...

Are Americans naturally more at risk of developing the disease?

OR...

Are American therapists more likely to diagnose it. This would be a clear case of ethnocentric bias in the diagnosis of DID.

"Psychometric" vs "psychological" tests...

Thigpen and Cleckley used a number of different tests on Eve. Some of the tests were psychometric and some were not:

Psychometric tests are ones that try to make a quantitative measurement of a psychological property. In this study the psychometric tests used are the IQ tests and the memory tests.

Other tests that were not psychometric include the Roschach tests and the drawing tests.

A common exam question might ask you about the tests performed by Thigpen and Cleckley, but it might ask specifically about either 'psychometric' or 'psychological' tests. For psychological tests you could mention any tests performed, but psychometric tests are more specific. Make sure you know which are which.

E.g." Describe the results of one psychometric test performed by Thigpen and Cleckley" (2)"Thigpen and Cleckley conducted a number of psychological tests on Eve. Describe two of them." (4)

... and projective tests?

Projective tests are designed to give an insight into a person's personality, often through them interpreting ambiguous images. See here for details of the ten projective inkblot (Rorschach) test images that Thigpen and Cleckley used.

Making links across the syllabus

Thigpen and Cleckley's interpretations and treatments of Eve were both very influenced by Freud's psychodynamic approach. Look back through the study and identify as many places as you can where Freud's theories are used. Of course this was also a case study, another similarity.

Exam hint: If they are using Freud's theories then this means that many of the evaluations of Frued's study will also be applicable to Thigpen and Cleckley's study. Two for the price of one! Make a list of these shared evaluation issues.

Are there any other links to other studies we've covered? Thigpen and Cleckley used an EEG on Eve, the same technique that Dement and Kleitman used (though with a very different research aim).

Assignment 1 - Practice paper 2 questions

2 Thigpen and Cleckley (multiple personality disorder) investigated Eve through hours of therapy and testing to find out more about her symptoms and help to treat her disorder.(a) What is meant by a psychometric test? [2](b) Describe the results of the psychometric tests used in Thigpen and Cleckley’s study. [3](c) Compare and contrast the psychometric testing approach as used by Thigpen and Cleckley with one other way of gathering data. [10](d) Discuss the extent to which individual and situational explanations of Eve’s behaviour are supported by Thigpen and Cleckley’s findings.(10)

Submit your answers through the form on the home page.

Revision

Watch the video and then fill in the summary sheet in as much detail as you can from memory.

Extension

Here is a great report into the controversy over DID. In fact, very few DID cases seem to show entirely distinct 'personalities' as Thigpen and Cleckley found. Instead, they may simply have a few different 'modes' - different ways of being themselves.

Do you think that 'extreme' DID cases like Christine Sizemore's actually exist?

This website would certainly say so. It is a site for 'survivors' of the condition and it contains a lot of interesting material, especially in the 'frequently asked questions' section.